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Rapidly growing primordial black holes as seeds of the massive high-redshift JWST Galaxies

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science china(Physics,Mechanics & Astronomy) 2024年第10期67卷 139-146页

作者： Guan-Wen Yuan Lei Lei Yuan-Zhu wang Bo wang yi-ying wang Chao Chen Zhao-Qiang Shen yi-Fu Cai yi-zhong Fan key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space science University of Science and Technology of ChinaHefei 230026China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Deep Space Exploration Laboratory/Department of Astronomy School of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China Jockey Club Institute for Advanced Study The Hong Kong University of Science and TechnologyHong KongChina

A group of massive galaxies at redshifts of z■7 have been recently detected by the James Webb Space Telescope(JWST),which were unexpected to form at such an early time within the standard Big Bang *** this work,we propose that this puzzle can be explained by the presence of some primordial black holes(PBHs)with a mass of~1000M_(⊙).These PBHs act as seeds for early galaxy formation with masses of~10^(8)-10^(10)M_(⊙)at high redshift,hence accounting for the JWST *** use a hierarchical Bayesian inference framework to constrain the PBH mass distribution models,and find that the Lognormal model with the M_(c)~750M_(⊙)is preferred over other *** rapidly growing BHs are expected to have strong radiation and may appear as high-redshift compact objects,similar to those recently discovered by *** we focused on PBHs in this work,the bound on the initial mass of the seed black holes remains robust even if they were formed through astrophysical channels.

关键词： primordial black hole dark matter halo black hole accretion primordial galaxies

Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

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science china(Technological sciences) 2024年第3期67卷 774-790页

作者： hu TeTe LU XinJiang yi Jian wang Yuhui XU Du State key Laboratory of Precision Manufacturing for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

High-Voltage and Fast-Charging Lithium Cobalt Oxide Cathodes: From key Challenges and Strategies to Future Perspectives

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Engineering 2024年第6期37卷 105-127页

作者： Gongrui wang Zhihong Bi Anping Zhang Pratteek Das hu Lin zhong-Shuai Wu State key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Dalian national Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Lithium-ion batteries(LIBs)with the“double-high”characteristics of high energy density and high power density are in urgent demand for facilitating the development of advanced portable ***,the lithium ion(Li+)-storage performance of the most commercialized lithium cobalt oxide(LiCoO_(2),LCO)cathodes is still far from satisfactory in terms of high-voltage and fast-charging capabilities for reaching the double-high ***,we systematically summarize and discuss high-voltage and fast-charging LCO cathodes,covering in depth the key fundamental challenges,latest advancements in modification strategies,and future perspectives in this *** and elaborated discussions are first presented on key fundamental challenges related to structural degradation,interfacial instability,the inhomogeneity reactions,and sluggish interfacial *** provide an instructive summary of deep insights into promising modification strategies and underlying mechanisms,categorized into element doping(Li-site,cobalt-/oxygen-site,and multi-site doping)for improved Li+diffusivity and bulkstructure stability;surface coating(dielectrics,ionic/electronic conductors,and their combination)for surface stability and conductivity;nanosizing;combinations of these strategies;and other strategies(i.e.,optimization of the electrolyte,binder,tortuosity of electrodes,charging protocols,and prelithiation methods).Finally,forward-looking perspectives and promising directions are sketched out and insightfully elucidated,providing constructive suggestions and instructions for designing and realizing high-voltage and fast-charging LCO cathodes for next-generation double-high LIBs.

关键词： Lithium cobalt oxide High energy/power density Fast-charging High-voltage Lithium-ion battery

Dietary sanguinarine supplementation recovers the decrease in muscle quality and nutrient composition induced by high-fat diets of grass carp(Ctenopharyngodon idella)

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Animal Nutrition 2024年第2期17卷 208-219页

作者： Yong Shi Lei zhong Yuanxiang Liu Shude Xu Jihong Dai Yaozhengtai Zhang yi hu Fisheries College Hunan Agricultural University hunan Engineering Research Center for Utilization of Characteristics of Aquatic Resources Hunan Agricultural University key Laboratory of Breeding Biotechnology and Sustainable Aquaculture Institute of Hydrobiology Chinese Academy of Sciences

The intake of high-fat diets(HFD) has been shown to diminish the muscle quality of aquatic ***, as an excellent additive, exhibits the capability to reduce fat deposition and alleviate inflammation. However, its role in the muscle quality reduction caused by HFD remains unclear. An eight-week trial was conducted to investigate the impacts of dietary supplementation of sanguinarine at1200 μg/kg(HFDS; crude fat = 10%) on the muscle quality of grass carp(Ctenopharyngodon idellus) in comparison to a basic diet(CON, crude fat = 5%). Each group had 3 replicates, with 40 fish per *** experiment employed one-way ANOVA and Duncan's multiple comparisons of the means. The results showed that the HFD exhibited lower growth performance, reduced protein deposition, myofiber diameter, and muscle hardness, coupled with higher levels of fat deposition and inflammation when compared with the CON. However, HFDS improved growth performance(P foundation for its practical implementation.

关键词： Plant extract Muscle feature Myofiber characteristics Muscular texture Protein metabolism

Simultaneously enhanced electrochemical performance and air stability of Ni-rich cathode with a modified washing process

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Rare Metals 2024年第1期43卷 87-97页

作者： Ben-Rui hu ying-yi Yuan Yu-Cheng wang Xun-hui Xiong School of Environment and Energy Guangdong Provincial Key Laboratory of Advanced Energy Storage MaterialsSouth China University of TechnologyGuangzhou 510640China

Water washing has been regarded as one of the most effective strategies to remove surface residual lithium of nickel-rich layered oxides for lithium-ion batteries(LIBs).However,the loss of lattice lithium during the water washing process deteriorates the electrochemical performances and air ***,washing the LiNi_(0.90)Co_(0.05)Al_(0.02)O_(2)(NCA) with ammonium dihydrogen phosphate(NH_(4)H_(2)PO_(4)) solution has been proposed to simultaneously enhance electrochemical performances and air stability,in which in-situ generated Li_(3)PO_(4) coating layer on surface of NCA can suppress the loss of lattice ***,as a fast ionic conductor,Li_(3)PO_(4) coating layer on NCA can prevent the direct contact with electrolyte/*** a result,the NH_(4)H_(2)PO_(4) solution washed NCA cathode can deliver a high capacity of131.9 mAh·g^(-1) at 10.0C rate as well as impressive cycle stability with a capacity retention of 83.1% after 100 cycles at 1.0C,much higher than those of water washed NCA(WS-NCA) *** exposed in air for 7 days,the NH_(4)H_(2)PO_(4) solution washed NCA electrode can more effectively maintain the structural integrity as well as the electrochemical performances than water-washed *** work provides a simple and effective approach to enhance the cycle stability and air stability of Nickel-rich cathode materials.

关键词： Layered Ni-rich cathode Residual lithium Li_(3)PO_(4)coating Rate performance Air stability

Cationic surface polarization centers on ionic carbon nitride for efficient solar-driven H_(2)O_(2) production and pollutant abatement

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Chinese Chemical Letters 2024年第10期35卷 383-388页

作者： Zhenyu hu Zhenchun Yang Shiqi Zeng Kun wang Lina Li chun hu Yubao Zhao MOE key Laboratory for Water Quality and Conservation of the Pearl River Delta Institute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou510006China

Solar-driven H_(2)O_(2)production and emerging organic pollutants(EOPs)elimination are of great significance from the perspective of environmental *** efficiency of the photocatalytic reaction system is the key challenge to be *** this work,the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is *** bipyridinium cation(TMAP)is complexed on a K^(+)-incorporated carbon nitride(CNK)framework,and the combination of local polarization centers both on the surface(bipyridinium cation)and bulk(K+cation)contributes to a superior photocatalytic H_(2)O_(2)production performance,affording a remarkable H_(2)O_(2)generation rate of 46.8μmol h^(-1)mg^(-1)and a high apparent quantum yield(AQY)value of 77.5%under irradiation of 405 nm *** substantiated experimentally by steady state/transient spectroscopy techniques,the surface local polarization centers increase the population of the long-lived trapped electrons,and thereby promote the interfacial charge transfer process for chemical conversion *** strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.

关键词： Local polarization Oxygen reductionreaction Hydrogen peroxide production Pollutantdegradation Polymeric carbon nitride

Advanced oxidation via the synergy of C-defective/C-O band modified ultrathin porous g-C_(3)N_(4)and PMS for efficient photothermal degradation of bisphenol pollutants and lignin derivatives

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Green Energy & Environment 2024年第7期9卷 1159-1170页

作者： Liquan Jing Meng Xie Yuanguo Xu chun Tong Xia Du Heng Zhao Na zhong huaming Li Jinguang hu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang212013China Department of Chemical and Petroleum Engineering University of Calgary2500 University DriveNWCalgaryAlbertaT2N1N4Canada School of Pharmacy Jiangsu UniversityZhenjiang212013China School of Material science&Chemical Engineering Harbin University of Science and TechnologyHarbin150080China Institute for Energy Research Jiangsu UniversityZhenjiang212013China

This work uses thermal polymerization of urea nitrate,oxyacetic acid and urea as the raw material to prepare ultra-thin porous carbon nitride with carbon defects and C-O band(OA-UN-CN).Density functional theory(DFT)calculations showed OA-UN-CN had narrower band gap,faster electron transport and a new internal construction electric ***,the prepared OA-UN-CN significantly enhanced photocatalytic activation of peroxymonosulfate(PMS)due to enhanced light absorption performance and faster electron *** the result,the OA-UN-CN/PMS could entirely degrade bisphenol A(BPA)within 30 min,where the photodegradation rate was 81.8 and 7.9 times higher than that of g-C_(3)N_(4)and OA-UN-CN,***,the OA-UN-CN/PMS could likewise degrade other bisphenol pollutants and sodium lignosulfonate *** suggested possible photocatalytic degradation pathways accordingly and explored the toxicity of its degradation *** work provides a new idea on the development of advanced photocatalytic oxidation processes for the treatment of bisphenol pollutants and lignin derivatives,via a metal-free photothermal-catalyst.

关键词： Photothermal-catalytic G-C_(3)N_(4) Peroxymonosulfate Bisphenol Sodium lignosulfonate

Thermal pretreatment of willow branches impacts yield and pore development of activated carbon in subsequent activation with ZnCl_(2) via modifying cellulose structure

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Chinese Journal of Chemical Engineering 2024年第5期69卷 227-237页

作者： Linghui Kong Chao Li Runxing Sun Shu Zhang yi wang Jun Xiang Song hu Dong wang Chuanjun Leng Xun hu School of Material science and Engineering University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China Shandong BASAN Graphite New Material Plant Zibo 255311China

Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the *** pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/*** might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic ***,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in *** thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of ***-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in *** thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280.

关键词： Thermal pretreatment Activation with ZnCl_(2) Willow branch Activated carbon Biochar

Localization of q-form fields on a de Sitter brane in chameleon gravity

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Frontiers of physics 2024年第3期19卷 11-18页

作者： yi zhong Tao-Tao Sui School of Physics and Electronics science Hunan UniversityChangsha 410082China Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of MoELanzhou UniversityLanzhou 730000China College of Physics Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Recently,it was found that the vector field can be naturally localized on the thick brane in chameleon *** this work,we extend this study to encompass de Sitter brane *** focus on the localization of q-form *** scalar and vector fields can be localized on the de Sitter brane,while the KR field cannot be *** condition for localization of the scalar and vector fields is ***,we investigate the localization characteristics in two examples with given conformal factor b(ϕ).In the first case,the effective potentials and KK modes of the matter fields are obtained asymmetric even though the de Sitter brane has Z2 *** the second case,volcano-like effective potentials are generated in the de Sitter brane model.

关键词： brane q-form field chameleon gravity